A longitudinal guide rail for a motor vehicle seat. The rail includes two elongated guide rails that engage with one another and are displaceable in relation to one another in the longitudinal direction of the rails, a retaining bracket for a seatbelt buckle, which is fastened to one of the two guide rails, a slot that is provided in one of the guide rails, through which a fixing section of the retaining bracket is guided into a space enclosed by the two guide rails and a fixing point, at which the fixing section of the retaining bracket is connected to one of the guide rails. The fixing section when viewed from the longitudinal direction of the rails, extends beyond the slot and the fixing point, also viewed from the longitudinal direction of the rails, is located at a distance from the slot.